Why Shania's Marriage Fell Apart

Shopping for groceries near her cottage in Huntsville, Ont., on May 16, Shania Twain—dressed down in a baseball cap, sunglasses and no makeup—was "smiling and chatting quietly with her sister Carrie-Ann," says an observer. "It was all very ordinary." But just a day earlier, there had been extraordinary news: Twain had suddenly split from her husband of 14 years, producer-songwriter Robert "Mutt" Lange. The separation came as a shock even to their friends. "When I last saw them, they were happy and affectionate," says a pal who saw the couple near their home in Switzerland this spring. "There was no sign there was any trouble. It doesn't make sense."

Sources say the 42-year-old country crossover superstar—who exploded on the music scene with 1995's "Any Man of Mine" and, under Lange's direction, had a string of hits including "You're Still the One" and "Man! I Feel Like a Woman!"—feels very much the same way. "She is devastated. This came out of left field," says an insider. "At 22, she was taking care of her entire family ... And then she met somebody who was like, 'I'm gonna take care of you.' She loved him." What went wrong? According to several sources, Lange's relationship with Marie-Anne Thiébaud, 37, a longtime secretary and manager of the couple's chateau in Switzerland, put an end to a romantic and professional partnership that has yielded three mega-selling albums, five Grammys and a 6-year-old son, Eja, on whom both doted. "Mutt and Marie-Anne left their spouses for each other and are still in a relationship," says a source close to the situation. Most devastating, says the insider, was that "Shania considered Marie-Anne one of her best friends." (Thiébaud could not be reached for comment.)

Reached in Montreux, Switzerland, hours after the split was announced, Lange, 59, a famously reclusive producer, told PEOPLE the separation was "an unfortunate thing that's happened." In fact, according to sources, Lange told Twain out of the blue that he wanted out of the marriage and acknowledged the alleged affair only after Twain, tipped off by a friend, confronted him. Lange denied to PEOPLE that he's in a relationship with Thiébaud ("It's not true") and said an alleged affair is "absolutely not the reason [for the separation]. It's literally just a growing apart, that's all."

Whatever caused the breakup Lange calls "irreconcilable," it is the end of a romance that was an integral part of Twain's fairy-tale rise from hardscrabble beginnings to superstardom. Raised in poverty in the Ontario mining town of Timmins by an Irish-Canadian mother and a stepfather who was a member of the Ojibwa tribe, Twain (born Eilleen Regina Edwards) helped support the family with singing gigs as a child. Her parents died in a car crash in 1987, when she was 21, and Twain—who later adopted the stage name Shania ("I'm on my way" in Ojibwa)—put her musical dreams on hold to provide for her three younger siblings. After scoring a Nashville contract, she caught the attention of Lange, who has worked with everyone from Def Leppard to Celine Dion. They married six months after they met. "We knew we wanted to be together for the rest of our lives," Twain told PEOPLE in '95.

Without Lange, the singer will carry on with the support of family and find solace in her first love, music. "Some of country's best songs have been about finding the strength to get over a broken heart," says a source. "Shania's greatest songs still have yet to be sung."